The present invention relates to a scroll-type fluid machine such as a scroll compressor or a scroll vacuum pump, and especially to a scroll-type fluid machine for improving cooling capability of air which is discharged from a scroll compressor.
When a scroll compressor is used as an air compressor, compression heat is generated during compressing operation and transmitted to each structural elements such as sealing members and bearings to decrease its mechanical life.
To prevent such problems, as shown in Japanese Patent Publication No. 9-53589A, in a conventional scroll compressor, a cooling path that communicates with external air is provided between the outer surface of a stationary scroll and casing, and between the outer surface of an orbiting scroll and an electric motor or a casing that enclose it to forward air with a cooling fan at one end of a compressor body, thereby cooling the stationary and orbiting scrolls and an electric motor, etc.
However, in the above scroll compressor, air in a compression chamber is indirectly cooled With the stationary and orbiting scrolls, but compressed air from the compression chamber is directly discharged from an outlet to the outside to make cooling capability lower.
Thus, when high-temperature air discharged from the compression chamber is stored in an air tank or used for an air tool, pressure-storage efficiency is decreased and the lives of the air tools are likely to decrease.
To solve the problem, a separate cooler is connected to the compressor to form a unit so that air discharged from the compression chamber may be cooled. But, addition of such a cooler makes the compressor unit larger to limit the place for installation of the fluid machine and increase manufacturing cost.